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authorJosé Fonseca <jrfonseca@tungstengraphics.com>2008-02-25 15:18:33 +0900
committerJosé Fonseca <jrfonseca@tungstengraphics.com>2008-02-25 15:18:33 +0900
commitb75706764b4cf18f3b41bf4a97d82b3c528064d8 (patch)
tree1436190093e7d00d7fa8ff0fb0e1b6a05cf38a7b
parentefd336887f9c46e66b304def0aa5fc5e16dc990f (diff)
Add Zack's comments about CSOs.
-rw-r--r--src/gallium/auxiliary/cso_cache/cso_cache.h51
1 files changed, 46 insertions, 5 deletions
diff --git a/src/gallium/auxiliary/cso_cache/cso_cache.h b/src/gallium/auxiliary/cso_cache/cso_cache.h
index b4f4f3ae41..3a005a376e 100644
--- a/src/gallium/auxiliary/cso_cache/cso_cache.h
+++ b/src/gallium/auxiliary/cso_cache/cso_cache.h
@@ -1,6 +1,6 @@
/**************************************************************************
*
- * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2007-2008 Tungsten Graphics, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
@@ -25,9 +25,48 @@
*
**************************************************************************/
- /*
- * Authors:
- * Zack Rusin <zack@tungstengraphics.com>
+ /**
+ * @file
+ * Constant State Object (CSO) cache.
+ *
+ * The basic idea is that the states are created via the
+ * create_state/bind_state/delete_state semantics. The driver is expected to
+ * perform as much of the Gallium state translation to whatever its internal
+ * representation is during the create call. Gallium then has a caching
+ * mechanism where it stores the created states. When the pipeline needs an
+ * actual state change, a bind call is issued. In the bind call the driver
+ * gets its already translated representation.
+ *
+ * Those semantics mean that the driver doesn't do the repeated translations
+ * of states on every frame, but only once, when a new state is actually
+ * created.
+ *
+ * Even on hardware that doesn't do any kind of state cache, it makes the
+ * driver look a lot neater, plus it avoids all the redundant state
+ * translations on every frame.
+ *
+ * Currently our constant state objects are:
+ * - alpha test
+ * - blend
+ * - depth stencil
+ * - fragment shader
+ * - rasterizer (old setup)
+ * - sampler
+ * - vertex shader
+ *
+ * Things that are not constant state objects include:
+ * - blend_color
+ * - clip_state
+ * - clear_color_state
+ * - constant_buffer
+ * - feedback_state
+ * - framebuffer_state
+ * - polygon_stipple
+ * - scissor_state
+ * - texture_state
+ * - viewport_state
+ *
+ * @author Zack Rusin <zack@tungstengraphics.com>
*/
#ifndef CSO_CACHE_H
@@ -36,7 +75,9 @@
#include "pipe/p_context.h"
#include "pipe/p_state.h"
-#include "cso_hash.h" /* for cso_hash_iter, as MSVC requires structures returned by value to be fully defined */
+/* cso_hash.h is necessary for cso_hash_iter, as MSVC requires structures
+ * returned by value to be fully defined */
+#include "cso_hash.h"
#ifdef __cplusplus